BIOL 301 Exam 1 Questions And Answers Complete
Solutions
What can distinguish between RNA and DNA? ANS Presence of 2' OH on RNA
A nucleosome is composed of how many total histone molecules? ANS 8
In terms of MNase digestion, a chromosome protects ___ base pairs, while a nucleosome protects
___ base pairs. ANS 166, 146
Adenine binds to Thymine by ___ hydrogen bonds, while Cytosine binds to Guanine with ___
hydrogen bonds. ANS 2, 3
The special sequence of centromeres provides what function? ANS Site for spindle fiber
attachment.
If it is known that a double-stranded DNA sequence is 20% adenine, what percentage is Guanine?
ANS 30%
In B-form DNA (the typical form of DNA in our cells), how many base-pairs are present in one
helical turn of the DNA? ANS 10
Who used DNase, RNase, and protease to prove that DNA was the "transforming agent" of
Strepococcus? ANS Avery, MacLeod, and McCarty
Who collected data on base rations (purines equal pyrimidines)? ANS Chargaff
Who built the first accurate model for the structure of DNA? ANS Watson and Crick
Who transformed Type IIR bacteria into Type IIS bacteria in mice? ANS Griffith
, Who used 32P and 35S to show the genetic information in bacteriophage T2? ANS Hershey and
Chase
What are the purines? ANS Adenine and Guanine
What are the pyrimidines? ANS Cytosine and Thymine
Who performed denaturation mapping of phage DNA to demonstrate bidirectional replication? ANS
Schnos and Inman
What enzyme in prokaryotes lays down the RNA primers on the lagging strand? ANS DNA
primase
Polymerases that "back up" to remove bases that were incorporated incorrectly are utilizing what
activity? ANS 3' to 5' exonuclease activity
Which enzyme extends the DNA at chromosomal ends? ANS Telomerase
What are the unique aspects of eukaryotic chromosome replication (as compared to prokaryotic
replication)? ANS Replication is restricted to S phase, there are many polymerases functioning at
the replication fork, there is more than one replicon per chromosome.
All DNA polymerases synthesize the new strand in what direction? ANS polymerases read 3' to
5' and synthesize 5' to 3'
The short synthesized fragments produced on the lagging strand of DNA replication were named
after whom? ANS Reiji and Tuneko Okazaki
What proteins unwind DNA (open it up) at the replication fork? ANS DNA helicases
Solutions
What can distinguish between RNA and DNA? ANS Presence of 2' OH on RNA
A nucleosome is composed of how many total histone molecules? ANS 8
In terms of MNase digestion, a chromosome protects ___ base pairs, while a nucleosome protects
___ base pairs. ANS 166, 146
Adenine binds to Thymine by ___ hydrogen bonds, while Cytosine binds to Guanine with ___
hydrogen bonds. ANS 2, 3
The special sequence of centromeres provides what function? ANS Site for spindle fiber
attachment.
If it is known that a double-stranded DNA sequence is 20% adenine, what percentage is Guanine?
ANS 30%
In B-form DNA (the typical form of DNA in our cells), how many base-pairs are present in one
helical turn of the DNA? ANS 10
Who used DNase, RNase, and protease to prove that DNA was the "transforming agent" of
Strepococcus? ANS Avery, MacLeod, and McCarty
Who collected data on base rations (purines equal pyrimidines)? ANS Chargaff
Who built the first accurate model for the structure of DNA? ANS Watson and Crick
Who transformed Type IIR bacteria into Type IIS bacteria in mice? ANS Griffith
, Who used 32P and 35S to show the genetic information in bacteriophage T2? ANS Hershey and
Chase
What are the purines? ANS Adenine and Guanine
What are the pyrimidines? ANS Cytosine and Thymine
Who performed denaturation mapping of phage DNA to demonstrate bidirectional replication? ANS
Schnos and Inman
What enzyme in prokaryotes lays down the RNA primers on the lagging strand? ANS DNA
primase
Polymerases that "back up" to remove bases that were incorporated incorrectly are utilizing what
activity? ANS 3' to 5' exonuclease activity
Which enzyme extends the DNA at chromosomal ends? ANS Telomerase
What are the unique aspects of eukaryotic chromosome replication (as compared to prokaryotic
replication)? ANS Replication is restricted to S phase, there are many polymerases functioning at
the replication fork, there is more than one replicon per chromosome.
All DNA polymerases synthesize the new strand in what direction? ANS polymerases read 3' to
5' and synthesize 5' to 3'
The short synthesized fragments produced on the lagging strand of DNA replication were named
after whom? ANS Reiji and Tuneko Okazaki
What proteins unwind DNA (open it up) at the replication fork? ANS DNA helicases
